The present invention relates to the field of temporary roadway sign stand devices. More specifically it relates to temporary roadway sign stand devices for positioning on irregular or sloping terrain.
There are literally millions of miles of highways and roadways crisscrossing the United States. And as any motorist might attest, there seems to be a never-ending need to build more roads or repair existing ones. Such constant road work is cause for concern if the area under construction is improperly marked for upcoming traffic. For this reason temporary roadway warning signs play a particularly important role in highway traffic safety, and it is extremely desirable that these signs are erected and remain in a manner which is readable to passing traffic, at all times and under most all conditions.
The nature of this field has been established by incremental improvements of numerous known features by those skilled in the relevant art. Generally temporary signs are designed to be easily assembled, moved about, disassembled, and transported by small road crews or sometimes by just a single person, such as the device shown in U.S. Pat. No. 4411085 to Farmer. It is also preferable that the display height of the sign should be adjustable, as shown in U.S. Pat. No. 4092792 to Vorhees. A temporary sign stand should also possess an adjustable means to accommodate different sign types and sizes. This feature is shown in U.S. Pat. Nos. 4882866 to Gebhardt, and 4717110 to Fohrman. Another desirable feature in temporary sign stands is the ability to stand upright on uneven or irregular terrain, as disclosed in the Dillon reference, and in U.S. Pat. No. 4888894 to Brown, Jr. Dillon uses a tripod base to overcome the problems presented by these rocky and rough surfaces, while Brown, Jr. offers four legs which are individually extendable to adapt to these surfaces as well. Other modest improvements to temporary sign stands are shown in U.S. Pat. Nos. 4817318 to Strauch; 4714220 to Hillstrom, et al.; 4694601 to Dicke, et al.; 4676015 to Stoudt; 4658527 to Pingel; 4507887 to Seely; 4498657 to Werner; 4310979 to Bloom; 4019271 to Latimer; 3899843 to Doyle, et al.; 3828455 to Bentley; 3620496 to Bolt, et al.; 3591116 to Dalum; 3519235 to Walter; and 3165847 to Gunderson.
Despite the seemingly large number of patents which may relate to this field, until the present invention there has remained the problem of unreadable traffic warning signs. The causes of this problem may be categorized in a number of ways, including those which relate to the placement of the temporary sign stand--where and how it is erected for display to traffic--and to the design of the sign stand--wind resistivity, stabilization, etc.
The first facet of unreadable signs which is addressed by the present invention involves sign placement. One of the specific causes which typically results in an unreadable roadway sign is due to temporary sign stands being erected on sloping terrain--which is distinguishable from uneven or irregular terrain. The sign will typically lean in the same direction of the slope and is usually easily knocked over by a cross wind or pulled to the ground by gravity. Even if it remains standing the angle at which the sign is presented to traffic may minimize its communication effectiveness. Occasionally this may be rectified by moving the sign to another, more level, location. In some areas the angled terrain of a "barrow pit" running parallel to the roadway cannot be avoided without positioning the sign very close to or on the roadway. Common sense dictates that this would not be proper because the sign stand might present a greater hazard than it prevents. The present invention, unlike any of the prior art, is designed to adjust to this incline and display the sign in a readable manner.
Although no prior art has been found which completely addresses this problem in the manner in which the present invention does, solutions have been sought. For example, the Pingel reference shows a design which will stand upright on a sloping terrain by varying the depths to which each leg support is inserted into the ground. Soft ground is not always available, however, and the Pingel sign stand would then be useless in situations of hard or rocky ground or roadway. There are also a number of patents for tripod type sign stands, for instance U.S. Pat. No. 4905391 to Dillon, and "quadruped" type signs, such as that shown in the Brown, Jr. reference, which address the problem of using temporary roadway signs on uneven or irregular surfaces--those containing rocks, holes and generally rough terrain--but not for sloping terrain, which may be just as prevalent along roadways. The present invention addresses these concerns in a manner that allows for sloping terrain as well.
Another specific cause of temporary road signs being unreadable is high wind conditions, which often exist on open roadways. The vacuum created by large trucks as they pass temporary roadway signs may also create this same effect. That is, temporary roadway sign stands of a design as shown in the Stoudt reference may bend backwards, or, as shown in the Seely reference, may twist or flap side-to-side thereby distorting the viewable message on the sign. In fact, it has been the focus of a number of references to allow such movement to spill the wind and effectively prevent the tipping of the apparatus. The present invention takes a different approach by rigidly resisting these forces, rather than accommodating them. This insures the readability and permanence of the temporary warning sign at all times.
While the basis of the present invention could be considered to be relatively fundamental, it is a fact that those skilled in the relevant art failed to realize the proper combination and selection of elements to solve the prior problems. Although the implementing arts and elements of the present invention were available, those in the field focusing on the problems of a proper temporary sign stand had not been able to solve these problems. Others skilled in the relevant art took the direction and focus of designing signs, and sign stands to accommodate the prevailing winds in a manner so as to avoid upending. This resulted in those skilled in the art teaching away from the direction of the present invention. While there had been substantial attempts by those skilled in the art at overcoming the problem of unstable sign stands, until the present invention such attempts had not resulted in an adequate economical solution to the problem.
Those skilled in the relevant art had possibly misidentified the problem of unreadable signs in roadway traffic as strictly a problem of signs tipping over. The present invention has viewed this as just one of the many causes to the underlying problem. The invention of this application addresses the problem of unreadable roadway signs, and has appropriately identified a variety of factors such as upending, twisting, improper placement and such, as the causes.